this was a personal moment for barack obama who talked about the influence of nelson mandela when he was a young man. >> reporter: that's right, john. it was just huge. president obama was 19 years old when he first got involved with the anti-apartheid movement. the first time he gave what being call a political speech was back in 1981. he was a sophomore at occidental college when he spoke out against apartheid. for president obama, nelson mandela was a personal hero and personal idol who struggled his earliest ambitions. >> i am one of the first who grew inspiration from nelson mandela's life. my first political action, the first thing i ever did that involved an issue of policy or politics was a protest against apartheid. >> reporter: they met in person only briefly in 2005 before obama became president. the two leaders, each standing in history as the first black president of his nation, spoke occasionally by phone. president obama penned the forward for mandela's 2010 memoir "conversations with myself." he wrote his example helped awakened me to the wider world and the obligatio